Memantine and Dextromethorphan Interaction
Drug interaction information between Memantine and Dextromethorphan.
Memantine and Dextromethorphan have a documented moderate interaction in FDA labeling.
FDA drug labeling documents a moderate-severity interaction between Memantine and Dextromethorphan. This page displays the available source-record category and label text. The category is not an individual risk estimate or medication-combination direction.
How They Interact
Both of these drugs affect the same receptors in the brain, and using them together has not been well studied. This could cause unknown side effects or change how the medications work.
FDA Label Information
7.2 Use with Other N-methyl-D-aspartate (NMDA) Antagonists The combined use of memantine hydrochloride with other NMDA antagonists (amantadine, ketamine, and dextromethorphan) has not been systematically evaluated and such use should be approached with caution.
Dextromethorphan Also Interacts With
- Safinamide major
- Rasagiline moderate
- Tranylcypromine moderate
- Abiraterone minor
- Aripiprazole minor
Frequently Asked Questions
What SPL severity band is on file for Memantine + Dextromethorphan?
Compiled FDA labeling labels this pair moderate. That is a source-record field, not an individual medication-combination decision.
Which drug in this pair has the larger labeled-interaction portfolio?
Dextromethorphan has 15 labeled pairs on file vs Memantine's 2. In the moderate band specifically: Memantine has 1; Dextromethorphan has 3 (also Rasagiline, Tranylcypromine).
What mechanism field is on file for Memantine and Dextromethorphan?
Both of these drugs affect the same receptors in the brain, and using them together has not been well studied. This could cause unknown side effects or change how the medications work.
Dextromethorphan carries more major-labeled pairs than Memantine
SPL source-record counts only. This page's band is moderate · classes on file: Memantine (NMDA Receptor Antagonist); Dextromethorphan (Antitussive).
Dextromethorphan has 1 major-labeled pair vs Memantine's 0. This page itself is in the moderate band, not the major band.
0 major · 1 moderate · 1 minor · 2 total
Memantine has no other moderate-band peer in this dataset besides Dextromethorphan.
1 major · 3 moderate · 11 minor · 15 total
- Other moderate peers for Dextromethorphan
- Rasagiline
- Tranylcypromine
Sources: FDA Drug Labels (SPL) via openFDA (2026). This is for informational purposes only and is not medical advice. This registry does not provide individual medication-combination directions.
Read our methodology - how this data is sourced, computed, and verified.